Impossible Difficulty Combat Guide
This guide is on tactical combat for Impossible difficulty. For advice on general strategy, see the Impossible Difficulty Strategy Guide article. = General information and advice = Sectoids — changes and tactical advice Unlike other difficulties, on Impossible, Sectoids have 4 HP. XCOM soldiers start with 3+1 HP. Given that Sectoid critical damage is 4 to 6, your soldiers will often die from a single enemy shot. The soldiers should be positioned behind full cover. You should flank the enemy whenever possible and destroy cover with Frag Grenades for a clear shot with rifles. Use a grenade to kill at least 2 enemies. When one or more Sectoids are flanked by one soldier, use Overwatch ability, they will do nothing while flanked (or exposed) + overwatched (only flanked Sectiods skipping their turn), but you must be behind cover (half or full) or they will shoot back (sometimes when the flanking soldier is low on health they will try to kill him/her). One soldier can disable a whole group of sectiod that way. To get into better position, always use full cover and hunker down, scatter your soldiers around the map so you can flank them, break line of sight if possible and sometime leave one soldier behind indestructible full cover + hunker down as bait. XComGame FlankGuide1.jpg XComGame FlankGuide2.jpg XComGame FlankGuide3.jpg Thin Men — changes and tactical advice On Impossible, Thin Men have 6 HP, and critical damage of 7 to 9. When fighting them, it is advisable to never engage when the enemy has visibility on your squad at the start of their turn. Cover is not very effective against Thin Men due to their Poison Spit ability, and they have a tendency to keep Overwatch, making assault against them problematic. You can counter this by retreating your squad far enough for the aliens to lose sight of them, then put your soldiers on Overwatch. In this case, the aliens will often advance, and get shot down by reaction fire. If the enemy survives their turn, you can dash back for a retreat and repeat the sequence, or advance if the enemy is retreating. Just like Sectoids, they will also skip their turn, if they are flanked (or exposed) + overwatched. However, there is a low - medium possibility that they will shoot back or use Poison Spit ability, but still it`s the best tactic to neutralize them. Best way to get into flanking position is to break line of sight and hide behind walls, trucks and bigger cars. They will advance towards you and using overwatch most of the time. Take a peak where they are, if flanking still not possible, hide again and wait one more turn. Another way to get rid of them is explosives, two grenades and a Rocket Launcher shoot can eliminate a whole group of Thin Men (your soldiers life is more important than a few weapon fragment) or just destroy their cover with one grenade, so they will be exposed to overwatch. Chryssalids — fighting strategy Chryssalids have 8 HP, so a combination of a Rocket from a Heavy soldier (6 damage points) and a Grenade (3 damage points) kills them right away. They don't have any weapons, so you are not losing anything by using explosives. With enough luck, it is possible to catch them in a single blast, as melee opponents tend to charge straight at your forces. Chryssalids have a "Hardened" property, which reduces the likelihood of being critically hit, so snipers will perform poorly against them. Since Chryssalids don't have ranged attacks and spend their turns at movement, Overwatch is very effective for granting free hits against them. If you can anticipate their approach by using a Sniper's Battle Scanner or reloading the game, you can essentially get a free turn against them by properly positioning with Overwatch. Additionally, highly ranked Assault soldiers with Close Combat Specialist ability get a free shot at an approaching Chryssalid. In conjunction with Run & Gun to get close to the enemy, and Rapid Fire for double shot, this can enable an Assault soldier to take three shots at the Chryssalid during one turn. Exploiting save / load to save your soldiers You can save your soldiers by reloading the game mid-mission, but if you repeat actions in the same order, all the same shots will hit and miss. The outcomes are pre-determined. This happens because the game "rolls the dice" for shots at the start of each XCOM turn. To get different outcomes, you need to change the order in which soldiers shoot and move, or move your soldiers on different positions. In short, you need to do things differently. By trying different order of actions, you can achieve 100% hit rate for your soldiers while never getting them shot. Unfortunately, this can't save soldiers from enemy melee attacks, because they always hit. =Tactical Guide= Despite the fact that there are many types of missions your real goal is always the same — to eliminate all enemy forces. On Impossible the enemy has superior numbers, hitpoints and firepower so trading shots cover to cover will not work in most situations. In other words, more advanced battlefield tricks will be required to beat this hell of a difficulty. Deployment On the Impossible difficulty every detail counts so you should make sure your team is deployed properly. When you pick your soldiers their position on the screen 1-2-3-4-5-6 translates into the following deployment formation: Make sure you check the gear of your soldiers, especially those returning from the infirmary. Until you press the "Launch Mission" button, you can always go back to Engineering and make some more gear. Scouting In X-COM Enemy Unknown scouting is very different from basic strategy games and from what one might do in real life. The most important thing to realize is that enemies will NOT shoot at you the same turn you discover them. They will only reposition, mainly to cover, which is usually within your visual range. The best way of scouting is sending a single scout ahead expending only 1 action. For this action you can completely ignore any cover as you will not use it anyway. If some enemies are discovered they will take cover after which your Sniper(s) can fire from a safe distance using Squadsight and the scout can retreat back to the team, which is waiting in cover. If your scout is Assault Class, which is recommended, you can even use Run and Gun to activate Overwatch after retreating. If the enemies charge next turn, you can hit them with reaction fire and then finish them off in your turn. If nobody comes, repeat step 1. If no enemy is found you can retreat back to the team and scout another direction next turn or you can move your team to the scout. When moving your team to the scout make sure you do not reveal any additional map squares. Failing to do is a good way to get your team wiped out. First move your Sniper if you need to. Then move your Heavy. They can both benefit from cover and should get the best spots in that order. Your Assault and Support soldiers should be then clustered as close to the first soldiers as possible so they can all take reaction shots if a patrol comes around. Once again, you are not going to get hit that turn so there is no risk of being hit by a grenade. Lastly, when moving your team, remember not to take any second action until the whole team is safely moved to the new location. This will allow you to run or fire if you accidentaly discover some enemies on the way. The 'most common mistake, ''which can be seen in many videos is this: You send a scout to location A, find no enemies so you move a few more soldiers to that position and go Overwatch. Then you decide you want to support that team and send another scout to position B. Position B can be right next to potition A, it can be well fortified and a logical place to move to. However, if you discover some enemies while moving to position B, you are in a tricky situation. Team B can fire but with only 1 action and without team A support. Team B can also retreat but that would expose team A. Therefore, '''never scout two locations in the same turns unless you have a very good reason or like to load a lot. Leaving one half of your team back may sound bad but in this game it works suprisingly well - same as clustering. Also, when moving soldiers, make sure all soldiers still have at least 1 action remaining. In other words, do not activate Overwatch or reload before moving your soldiers. This mistake is also nicely shown and explained in the beginning of this video. Any class can scout but the Assault Class works best for obvious reasons. Run and Gun will allow you to Overwatch when you have to retreat to cover, Lightning Reflexes will enable you to look for enemies that are already active and the other abilitiees makes the Assault Class by far the most durable. As scouting can require a lot of retreating, assault rifles are preferable to shotguns. Armor choice depends on the map. Basically, you should be able to check rooftops if there are any. Use the grappling hook carefully though, as it can sometimes take you to places that are difficult to retreat from. The Hover S.H.I.V. is a good alternative especially for missions taking place on multiple levels. However, few players spend resources to develop these on impossible difficulty. Take your time. In all but two types of infrequent missions time is on your side. So, reload, improve your position and listen for those lovely noices that tell you where the enemy is. Most battles are not lost to a tactical mistake but rather to a lack of patience - you'll need a lot of it for Impossible Ironman. Count your targets. If you engage more than 3 targets it is a good idea to take notes, especially early on. Knowing whether you have to use cover when scouting is essential and a loose enemy that drops a grenade on a clustered team is devastating. Sniper combat As said above, the enemy has superior numbers, hit points and firepower. What do we have? Snipers! Their long range is something the enemy lacks and you can abuse it in every and each mission. The key element here is Squadsight, which not only enables you to cover your team but can also be used for some "hit and runs" and "surprise shots". Positioning the snipers should be the highest priority. In bigger maps cover is not as important as line of sight. Plan a few turns ahead and place them so you don't have to move them all the time. They should be the first to get the Skeleton Suit, which can get them to position in turn 1. Archangel Armor is even better but doesn't have to be rushed. The "hit and run" tactic is quite simple. Send a scout (Assault Class works best) forward spending 1 action, shoot targets with snipers, pull the scout back. Repeat. This should be the standard scouting tactic and is further described in the Scouting section. "Surprise shots" can be made using a Battle Scanner or Ghost Armor. To get the most of it, throw the scanner, wait a turn, put all but one snipers into Overwatch, then shoot the target with the most HP. Enemies will run for cover, suffer some reaction fire and then you have another turn to finish them off. This tactic is better than "hit and run" and should be used in small maps, places with bad cover and areas where you expect heavy resistance. "Ghost Armor Annihilation" 'combines the most overpowered ability (Squadsight) with the most overpowered armor (Ghost Armor). All you need to do is to go invisible, approach the enemy and let the snipers have their fun. A team of four ghosts and two snipers can clear most maps without giving the aliens a single chance to fire. The same goes for the final boss who can be sniped all the way from the door. However, note that Close Combat Specialist trigger will break your cover whether you wish it or not. 'Snipers should be the last ones to shoot in most situations. If you have a huge mob incoming, dispatching the first wave with other soldiers will save Double Tap for a harder wave that might be coming. Also, note that thanks to Opportunist, snipers are better reaction shooters than all but Rapid Reaction Heavy Class. Due to Squadsight they can usually shoot anything that remains and they usually have a very decent chance to hit making them quite reliable at cleaning up. However, sniping first is an advantage when you deal with high HP enemies. The huge crit chance of snipers combined with Headshot will allow you to one shot a lot of enemies so shooting at them with less potent squad members could be a waste. Keep in mind the huge crit chance of sniper rifles and expect that you will often deal more damage than is shown. Therefore do not waste your sniper shots on low hp targets that can be easily finished off by other team members. You need 2-3 snipers for this strategy to work on Impossible. Note that they synergyze really well due to the Battle Scanner ability as each scanner can serve all your snipers. Suggested abilities: # Headshot - Don't forget to use this one. Can be used with Double Tap. Yes, you can crit robots. # Squadsight = Godmode. Snap Shot is really not an option here. # Gunslinger is ahead of Damn Good Ground as snipers tend to fly a lot later on and don't really need that aim. # Battle Scanner allows you to spot and kill whole groups of enemies while Disabling Shot only kinda disables one enemy. # Opportunist is a clear choice as Executioner is almost useless. # Low Profile enables you to leave that full cover to your squadmates. Keep in mind that you have it. # Double Tap is probably the second most powerful ability in the game right after Squadsight. You should do your best to level your snipers to Squadsight ASAP. Once there start worrying about the snipers stealing all the kills. As for Terror Missions, a trained rank 3+ sniper is quite usefull early on. With Gunslinger a conventional pistol is almost as good as a conventional assault rifle dealing the same base damage and only missing the 10% crit chance which is negligible as you are bound to take a few Headshots anyway and not having to reload is great in Terror Missions. This is a good reason for taking Gunslinger over Damn Good Ground. The problem of DGG is that there are few opportunities to climb stuff early on when you could use the extra aim. Later, you can climb those buildings but don't really need the aim that much and much later you'll be flying, which is where Damn Good Ground becomes quite useless. Alternative Tactics Beeline techs / Key Breakpoints: * Asia is statistically the best start, as abduction missions increase panic in a whole region, so europe and asia - with 4 nations each - will add the most panic per abduction. As you will always get your region bonus no matter how many countries of your origin region leave, you are best off starting in Europe or Asia. As Europe grants the most money for satellites, that makes Asia the ideal start. * Satellites are always priority #1, so that makes Workshop, Satellites, and Satellite Uplinks key. The need of workshops depends on the number of engineers you get from missions. Generally, it is a better idea to take engineers as rewards for abductions because if you take the cash, you'll end up spending it on Workshops and Generators to power them. * In Abduction Missions, find which abduction will prevent the most nations from going to 5 panic, then if there is a tie Sniper (if you need one) >engineers>money>scientists>Support/Assault/Heavy. * Squad Size I and II are by far the most important Officer Training School upgrades and ought to be taken month 2, 3 at the latest. * You want precision lasers by the first terror mission - this will be the hardest fight in the game and it's night and day to have the snipers with laser snipers and Laser Rifles / Scatter Lasers out there to deal with the cryssalid swarms instead of the default equipment. Some players, however prefer to go for Carapace Armor first, then straight to plasma weapons. This takes a lot of experience as you'll have to be able to capture a lot of aliens fast. Remember that even if a lot of civilians die you will still complete the mission and reduce the panic in the country. This is definitely preferable to losing your team so tread carefull. * You want Carapace Armor by the time mutons start showing up (month 3), so that soldiers can reliably survive a hit from their plasma rifles. * Ammo Conservation is the most important foundry upgrade, research Muton Autopsy and get 6 Muton Corpses stat for month 3. * At this point, if you fed your sniper kills, you should be able to snowball your advantages into a win. Success in the first 3 months is everything. Category:Guides